


def is_isbn_or_key(word):
    isbn_or_key='key'
    if len(word)==13 and word.isdigit():
        isbn_or_key = 'isbn'
    short_word=word.replace('_',' ')
    if'_' in word and len(short_word)==10 and short_word.isdigit():
        isbn_or_key = 'isbn'
    return isbn_or_key